Altec 1567 Mod:
This Mod came about at the request of some customers who noted the fantastic sonic characteristics of the Altec 1567 Mixer due to good sounding tubed mic pres, but found some significant drawbacks that prevented the practical use of the unit in music production.
The Drawbacks :
The EQ, when not needed, still added noticable hiss to the output.
This unit has a mono output, and it’s unusual to be summing 4 mics in modern music production. Most Altec 1567 owners are only using the unit for amplification of one, or at most two mics. Yet s..

Altec 1591A Mod:
This Mod came about at the request of some customers who favored the fantastic sonic characteristics of the Altec 1591 Compressor, but found the excessive gain of the input stage to be a significant drawback in that it severely over-compressed normal level signals.
The Drawbacks :
To avoid over-compression the input level controls are set so low that fine control of level becomes difficult. With the input levels set so low the output signal is just too noisy.
The release times are too long
The Solution :
A switch is added on the rear of the f..

Ampex 350 Mic Pre Optimizaton Mod:
This mod turns a somewhat unusable Ampex 350 electronics channel into one of the most impressive mic pres ever! Capitalizing on a fantastic design by the brilliant Ampex engineers this mod eliminates drawbacks to practical use in the recording of music while preserving and even teasing out a bit more of the inherent impressive sound. The result is totally usable hot neon like sound that is unmatched by other mic pres, a close second perhaps being the Neumann V76. This modified mic pre has all-around utility: it is thunderously punchy, has a w..

Ampex AM-10 Mic Pre Mixer Mod:
The Ampex AM-10 is a fine little mixer from the early/mid transistor era. The circuitry is very basic Class A resulting in an overall smooth, clean sound. The microphone input transformer is interesting in that it is very small...sometimes referred to as a “thumb” transformer. Usually a small transformer lacks low end response, as theory says it will saturate easily and thus attenuate peaks of low frequency signal. Somehow the thumb transformer in the AM-10 is able to pass low frequencies with minimal saturation. The saturation or loss of low freq..

Ampex MX-35 Mic Pre Mixer Mod:
The Ampex MX-35 is a fine little mixer from the late tube era. The circuitry is straight forward Class A (as are most tube circuits) resulting in an overall smooth, clean sound. The microphone input transformer is interesting in that it is very small...sometimes referred to as a “thumb” transformer. Usually a small transformer lacks low end response, as theory says it will saturate easily and thus attenuate peaks of low frequency signal. Somehow the thumb transformer in the MX-35 is able to pass low frequencies with minima..

Focusrite 315 Mod
This mod is intended to improve the transparency of the Focusrite 315. As the 315 is primarily used by Mastering Engineers it is they who have noticed a lack of transparency not only when the EQ is engaged, but even when it is inserted in the signal chain with EQ bypassed.
The Problem:
Too many audio coupling caps in the signal chain
The balanced input stage circuit is overdesigned and a signifiant cause for the lack of transparency
On transformer balanced models the transformers are not totally transparent. Rarely if ever is a transformer “transparent” to the exte..

Gates SA 39 mod:
This mod turns a somewhat unusable Gates SA39 limiter into one of the most impressive limiters ever! Capitalizing on a fantastic design by the brilliant Gates engineers this mod eliminates drawbacks to practical use in the recording of music while preserving and even teasing out a bit more of the inherent impressive sound. The result is a totally usable fat, warm and punchy sound equal to but not surpassed by just a few other similar units. It does improve the sound passing through it. It calls attention to the instrument or vocal being recorded.&n..

Orban Optimod 8100A and 8180A mod:
The Orban 8100A and 8180A processors were originally designed for broadcast audio ( radio and tv stations), with secret circuitry to keep high frequencies optimized even when the received signal is weak or wavering, such as near the edges of a broadcast stations allotted range. Additionally these processors evened out high frequency differences between songs, commercials and announcer voice. These processors and others like it can actually improve a recording that is a bit dull relative to the norm, and record buyers have often remarked that the vinyl or cd etc they purchased did not ..

Phase Linear 400 Mod:
The Phase LInear 400 and 700 amplifiers are among the best ever transistor amplifiers ever sold. The circuit is an excellent example of both simplicity and sophistication. A huge, high quality power transformer backs of the need for transient handling typically needed to reproduce music. The large number of output transistors allows for music to to spend more time in the more linear part of the transistor. Opinions as to the excellence of the circuit may vary, but the experience of the sound and music reproducing capabilities of this is hard to dispute. For one thi..